MII implementation of WECo rule. Zone A

[Former Member]

Dear Forum,

I would like to configure the SPC chart in MII to have an alarm when a data point falls beyond 3 standard deviations from the center line. The zone A alarm is activated when the data point falls in zone A or beyond (this is between 2 and 3 sd, and beyond) if i understand correctly.

Is there any way to have only the points beyond zone A or am i wrong in the understanding of the rule?

I'm using MII 11.5

Thanks in advance for the help,

Jose Luis

[Former Member]

Thank you Diana.

I think you're rigth. The control limits correspons to the 3 standard deviations. Therefore this alarms should solve the issue.

We will implement it this way.

Regards

[Former Member]

Hi Jose,

I not an SPC expert by far, but from what I seen, it looks like the areas of standard deviation fall between the Control Limits. Perhaps it would be possible to use the Control Limit Alarm, which would alarm a single point outside of the Control Limits.

I know that Zone A is the region between two and three standard deviations from the centerline, so I don't see that this alarm would work for points outside of 3 standard deviations.

Kind Regards,

Diana Hoppe